AKT1 and cancer: Claudins have also been demonstrated to activate many other signaling pathways and proteases, including phosphoinositide-3-kinase/protein kinase B (PI3K/Akt), mitogen-activated protein kinase (MAPK), Janus kinase/signal transducer and activator of transcription (JAK/STAT), metalloproteinases (MMPs) and microRNAs (miRs), thus contributing to various hallmarks of cancer (Supplementary Table S2).